Bluegrass plant

ABSTRACT

A Kentucky bluegrass plant which exhibits an attractive dark green color, rather narrow leaves and low rhizomatous growth habit and high density of shoots. It has a very large seed size and shows good resistance to Helminthosporium leaf spot, Mildew and Stripe smut diseases.

BACKGROUND OF THE INVENTION

This invention relates to a new and distinct variety of bluegrass plant, the novel characteristics of which reside particularly in its very attractive dark green color, which is maintained well throughout the growing season, a rather narrow leaf blade, large seed size and good resistance to common turf diseases, particularly leaf spot, stripe smut and mildew.

This new variety was discovered in plant material collected at the Lidingo Golf Course, Sweden. Selections within the plant material have been made towards a plant with dark green color, rather narrow leaves and good resistance to Helminthosporium. This plant was reproduced asexually by vegetative reproduction. After growth in a greenhouse, the vegetatively reproduced plants were transferred to field nurseries for increase and subsequent turf evaluation. Progeny tests were conducted and showed that the plant could be reproduced asexually by means of disseminules. The plant was thereafter identified as WK 411 bluegrass.

WK 411 exhibits a unique combination of characteristics which distinguishes it from all other varieties of which applicant is aware. Of special moment is its attractive dark green color in combination with narrow leaves and excellent resistance to stripe smut disease caused by the fungus Ustilago striiformis. The new variety exhibits good to excellent resistance to powdery mildew disease caused by the fungus Erysiphe graminis and to leaf spot caused by the fungus Helminthosporium vagans. WK 411 Kentucky bluegrass greens up early in the spring and maintains an attractive dark green color throughout the growing season. The variety is highly apomictic and has a turf-type growth habit tolerant to moderately close mowing.

A primary object of the invention is to provide a new and distinct bluegrass plant having the desirable characteristics referred to above and to be described in detail below.

Other objects and advantages of the invention will become more fully apparent from the following detailed description when taken in conjunction with the accompanying illustrations in which:

FIG. 1 shows a plant of the new variety approximately 4 weeks before the flowering stage.

FIG. 2 shows a plant of the new variety about 2 weeks after the completion of the flowering stage.

FIG. 3 shows a panicle of the new variety about 2 weeks after completion of the flowering stage.

PLANT DESCRIPTION

WK 411 bluegrass (Poa pratensis) is a perennial with creeping rhizomes, forming a dense, moderately low-growing compact turf. The variety possesses the following unique combination of characteristics:

1. Very good resistance to the stripe smut disease caused by the fungus Ustilago striiformis.

2. Good resistance to the leaf spot disease caused by the fungus Helminthosporium vagans.

3. Good resistance to powdery mildew caused by the fungus Erysiphe graminis.

4. Very good cold tolerance and winter survival.

5. An attractive dark green color during the entire growing season from early spring to late fall.

6. A narrow leaf blade, which makes WK 411 compatible with fine-leaved grasses, e.g., red fescue in mixtures.

7. Good rhizome and tiller development, forming a turf of superior density and good spreading ability.

8. Prostrate growth habit allowing close mowing.

9. Very good turf performance.

10. Very large seed, thousand kernel weight 0.45 g.

Morphological Description

The plants of the new variety described below were grown in South Sweden, lat. 56° N.

roots: Rhizomes of medium length, average 52 mm., see Table 1, below:

                  Table 1                                                          ______________________________________                                         Rhizome Development in 3-month Old                                             Kentucky Bluegrass Plants (South Sweden)                                                            Total length in                                                                             Length in                                            No. of rhizomes                                                                             mm. of rhizomes                                                                             average per                                  Variety Average per plant                                                                           Average per plant                                                                           rhizome, mm.                                 ______________________________________                                         Merion  2.4           79          33                                           WK 411  2.9          151          52                                           Sydsport                                                                               2.7          168          62                                           ______________________________________                                    

Leaves: Flag leaf is relatively short, dark green with blades 4-5 mm. wide and 47-67 mm. long. WK 411 has weak anthocyanin coloring of the leaf sheath in the young stage. Leaf sheath base is keeled, glabrous and glaucous. The ligule is of medium size, slightly pointed and is hairy.

Straw: Of medium length, plant height 65-70 cm.

Panicle: Pyramidal with main axis erect and top slightly drooping. Side axis at the bottom are horizontal. Panicle length 120-130 mm. Panicle slightly anthocyan colored. Lemmas are glabrous with indistinct intermediate nerves and scant basal webbing. The keel and lateral nerves are slightly pubescent. For further floret characteristics, see Table 2, below:

                  Table 2                                                          ______________________________________                                         Floret Characteristics of                                                      WK 411 Bluegrass (Oregon Grown)                                                Character             Description                                              ______________________________________                                         1.   Intermediate nerves on                                                                          Indistinct                                                    lemma                                                                     2.   Lemma color      Light straw color to uniform                                                   brown, lighter seeds often                                                     with dark spot near base.                                3.   Lemma margins and apex                                                                          Apex semi-flared from sharp                                                    keel-tapered to medium point                                                   in side view. Wide hyaline                                                     margins especially in basal                                                    florets. Margins tend to                                                       enclose palea in middle and                                                    terminal florets.                                        4.   Lemma texture    Finely granular                                          5.   In lateral plane - floret                                                                       Lemma evenly arched. Mass                                     shape plus thickness or                                                                         of seed greatest about middle.                                plumpness                                                                 6.   Palea            Finely granular, coarse teeth                                                  extending to near apex.                                  7.   Length           2.4 to 3.5 mm. (average                                                        2.9 mm.).                                                8.   Width            0.6 to 0.8 mm. (average                                                        0.7 mm.).                                                ______________________________________                                    

Seed: Very large seeded, average length 3.0 mm. and width 0.7 mm., see Table 3, below. WK 411 contains about 1,008,000 seeds per pound (0.450 grams per 1000 seeds) compared with Merion bluegrass, which is said to contain 2,100,000 seeds per pound.

                  Table 3                                                          ______________________________________                                         Seed Measurements                                                              South Sweden 1971-73                                                           Variety    Seed Length, mm.                                                                               Seed Width, mm.                                     ______________________________________                                         WK 411     3.03            0.72                                                Fylking    2.80            0.73                                                Merion     2.31            0.74                                                Windsor    2.20            0.59                                                Nugget     3.33            0.77                                                ______________________________________                                    

For morphological comparisons see Table 4, below:

                                      Table 4.                                     __________________________________________________________________________     Morphological comparisons and observations in WK 411 and other Kentucky        bluegrasses. (South Sweden)                                                    Planted 1971                                                                           Plant height, mm                                                                           Flag leaf length, mm                                                                       Flag leaf width, mm                                                                        Panicle length,                    __________________________________________________________________________                                                 mm                                 Variety 12 . 6 . 73 4 . 6 . 73  4 . 6 . 73  12 . 6 . 73                        WK 411  695         66.5        5.2         130.7                              Baron   619         36.5        5.0          82.8                              Fylking 720         65.8        4.8         123.9                              Newport 868         80.3        4.7         129.7                              Nugget  500         49.5        4.7          71.8                              Merion  828         87.8        5.5         120.3                              Primo   841         55.8        4.6         119.9                              Planted 1973                                                                          Ear emergence                                                                          Flowering                                                                              Plant height, mm                                                                         Flag leaf length, mm                                                                      Panicle length,                    __________________________________________________________________________                                                 mm                                 Variety                                                                               1974                                                                               1975                                                                               1974                                                                               1975                                                                               1-7-74                                                                              3-7-75                                                                              27-5-75    3-7-75                             WK411  15.5                                                                               23.5                                                                               4.6 10.6                                                                               654  714  47.1       131.6                              Belturf                                                                               15.5                                                                               20.5                                                                               8.6 13.6                                                                               688  770  59.8       118.8                              Adelphi                                                                               13.5                                                                               20.5                                                                               5.6 13.6                                                                               548  833  41.4       114.5                              __________________________________________________________________________

Turf Performance

Turf performance and spring color ratings for WK 411 and other Kentucky bluegrasses for the years 1969-1973 at New Brunswick, New Jersey, are presented in Table 5, below:

                  Table 5.                                                         ______________________________________                                         Regional Bluegrass Variety Test Established September 1968 at                  Rutgers University, New Brunswick, New Jersey.                                         Turf Quality Ratings                                                                            Spring Color                                                  9 = Best         9 = Best                                              Variety   1969   1970   1971 1972 1973 April 10, 1972                          ______________________________________                                         Majestic  7.9    7.9    6.8  6.5  6.8  8.0                                     WK-411    6.8    6.8    6.3  6.1  6.6  5.7                                     Fylking   7.3    7.2    6.7  6.9  6.5  5.0                                     Belturf   6.8    7.1    6.3  5.3  6.3  5.0                                     Pennstar  7.2    7.0    6.5  6.8  6.2  5.0                                     Nugget    8.1    6.9    6.5  4.9  5.2  1.0                                     Windsor   4.5    4.5    4.7  4.2  4.8  4.7                                     Merion    6.6    6.9    4.7  3.2  3.4  3.3                                     Primo     5.6    4.3    3.8  2.9  2.9  2.7                                     Park      4.7    3.9    3.6  2.9  2.3  5.3                                     Delta     2.9    2.5    2.5  2.1  1.7  4.0                                     S. Dak. Cert.                                                                            3.4    2.7    2.4  1.9  1.6  3.0                                     ______________________________________                                    

Turf quality ratings for WK 411 and other Kentucky bluegrasses for the years 1969-1971 at Rhode Island are presented in Table 6, below:

                  Table 6.                                                         ______________________________________                                         NE-57                                                                          Regional Project                                                               Location: Area I -- Sec.B. South                                               KENTUCKY BLUEGRASS VARIETY EVALUATION                                          University of Rhode Island                                                     Mowing Height 3/4" Low                                                                     TURF QUALITY                                                                   9 = Ideal Turf                                                                 1 = Bare Ground                                                    NO.   SELECTION   1969    1970  1971  AVERAGE                                  ______________________________________                                         52    Baron       7.8     7.2   7.1   7.37 abc                                 16    Merion      7.7     7.1   7.1   7.30 a-e                                 20    WK 411      7.4     7.0   7.2   7.23 a-e                                 7     Nugget      7.2     6.6   7.6   7.13 a-f                                 26    Belturf     7.9     6.5   6.5   6.97 a-g                                 10    Pennstar    7.7     6.5   6.5   6.90 a-g                                 15    Fylking     7.8     6.3   6.5   6.87 a-g                                 24    Primo       7.3     5.6   5.6   6.17 e-i                                 3     Windsor     5.9     5.8   6.4   6.03 f-i                                 12    Park        5.9     3.3   4.7   4.63 k-l                                 17    Delta       5.7     3.2   4.6   4.50 l                                   ______________________________________                                          Values followed by the same letter are not significantly different at the      5% level using Duncan's multiple range test.                             

Color ratings for WK 411 and other Kentucky bluegrasses for the years 1969-1973 at the University of Maryland are shown in Table 7, below:

                  Table 7.                                                         ______________________________________                                         1973 Kentucky Bluegrass Data                                                   University of Maryland                                                         Hopkins Research Farm                                                          1.5" Mowing Height                                                             Color Ratings (0-9)                                                            9 = Dark Green 0 = Bleach Tan                                                  Variety  1969   1970   1971 1972 1973 Color Average                            ______________________________________                                         Windsor  6.26   4.58   5.80 6.21 5.99 5.76                                     Nugget   6.92   4.20   6.09 5.92 6.83 5.89                                     Pennstar 7.14   4.54   5.92 6.59 6.77 6.19                                     Park     6.26   4.58   5.05 5.83 5.72 5.48                                     Fylking  7.14   4.95   6.40 6.63 6.88 6.40                                     Merion   6.54   4.45   6.44 6.58 6.83 6.17                                     Delta    5.88   4.46   5.09 5.75 6.85 5.60                                     WK-411   7.06   4.87   6.74 6.39 7.16 6.44                                     Primo    6.34   4.25   5.65 6.88 6.44 5.91                                     Belturf  6.74   4.54   6.09 6.29 6.16 5.96                                     ______________________________________                                    

Density ratings for WK 411 and other Kentucky bluegrasses for the years 1969-1973 are shown in Table 8, below:

                  Table 8.                                                         ______________________________________                                         1973 Kentucky Bluegrass Data                                                   University of Maryland                                                         1968 Hopkins Farm                                                              1.5% Mowing Height                                                             Turf Density (0-9)                                                             9 = Maximum Density 0 = Bare Ground                                            Variety  1969   1970   1971 1972 1973 Density Average                          ______________________________________                                         Windsor  7.18   7.58   6.35 6.25 6.26 6.72                                     Nugget   6.70   6.45   4.59 5.83 5.86 5.88                                     Pennstar 6.95   7.37   6.28 6.37 6.39 6.67                                     Park     7.24   7.04   6.14 5.08 5.39 6.17                                     Fylking  7.32   7.58   6.46 6.38 6.26 6.80                                     Merion   7.24   7.58   6.77 6.87 7.13/                                                                               7.11                                     Delta    6.18   5.66   4.16 5.17 5.19 5.27                                     WK-411   6.95   7.50   7.00 7.21 7.33 7.19                                     Primo    6.57   7.33   6.82 6.46 6.06 6.64                                     Belturf  7.14   7.66   6.40 5.71 5.73 6.53                                     ______________________________________                                    

As can be seen in Tables 5 and 6, WK 411 has shown consistently high turf performance. Table 7 shows that WK 411 has a very attractive dark green color, and the variety stays green from early spring (Table 5) to late fall. Table 8 indicates that WK 411 forms a very dense and good turf.

Disease Resistance

Disease resistance ratings for WK 411 and other Kentucky bluegrasses at New Brunswick, N.J. in 1972 are demonstrated in Table 9, below:

                  Table 9.                                                         ______________________________________                                         Regional Bluegrass Variety Test Established September 1968, at                 Rutgers University, New Brunswick, New Jersey.                                          Leaf Spot   Stripe Smut                                                        Percent Disease                                                                            Infected Tillers/ft..sup.2                                           Apr. 10  June 5   May 10                                            Variety    1972     1972     1972                                              ______________________________________                                         Majestic   7        7        30                                                WK-411     23       12       2                                                 Fylking    8        7        20                                                Belturf    27       33       26                                                Pennstar   10       8        14                                                Nugget     3        2        4                                                 Windsor    33       72       273                                               Merion     68       33       433                                               Primo      88       83       213                                               Park       65       95       11                                                Delta      85       89       69                                                S. Dak. Cert.                                                                             92       95       4                                                 ______________________________________                                    

The figures indicate that WK 411 has a very good resistance to leaf spot caused by the fungus Helminthosporium vagans and to stripe smut caused by the fungus Ustilago striiformis.

Reproduction and Propagation

Asexual reproduction of the new variety by disseminules (modified caryopses produced by agamospermy) has consistently produced progeny indistinguishable from the mother plant. 

What is claimed is:
 1. A new and distinct variety of Kentucky bluegrass plant, substantially as described and illustrated, characterized particularly by very good turf performance, very attractive dark green color, good rhizome and tiller development, very large seed and good resistance to leaf spot and stripe smut. 